1. Field of the Invention
The present invention relates to mobile terminal apparatuses suitable for use as mobile devices, such as a mobile phone, a personal handyphone system (PHS), a personal digital assistant (PDA), a mobile game device, and a digital camera, which include a first housing and a second housing that can be set to an open state or a closed state by sliding the first and second housings along each other.
More specifically, the present invention relates to a mobile terminal apparatus in which, when the first and second housings are set to the open state by sliding the first and second housings along each other, a keyboard provided on the second housing and a display unit provided on the first housing are positioned on the same plane so that the area in which the keyboard is exposed is increased and an input operation can be easily performed on a large input operation surface.
2. Description of the Related Art
Japanese Unexamined Patent Application Publication No. 2005-167847 (hereinafter referred to as Patent Document 1) discloses a mobile communication terminal with which a sliding operation can be easily performed. This mobile communication terminal includes a display housing provided with a display unit and an operation housing provided with a button operation unit. The display housing is slidable along the operation housing, and the state of the mobile communication terminal can be switched between an exposed state in which the button operation unit is exposed and a covered state in which the button operation unit is covered by the display housing in response to the sliding operation of the display housing.
A first helical compression spring is disposed in an antenna containing section provided in the operation housing, and the operation housing is urged by an urging force of the first helical compression spring in a direction for changing the state of the mobile communication terminal from the covered state to the exposed state. Thus, the sliding operation of the display housing in the process of setting the mobile communication terminal to the exposed state is facilitated.